Educational Content

Educational Content:

Here is information on few cardiological services. The information is aimed at patient education.

Coronary Angiography:

What is Coronary Angiography?

A coronary angiography is a special X-ray of the arteries which supply blood to the heart muscle.

This will show your doctor if you have coronary artery disease. And if so, where and how severe the narrowings in your arteries are.

The results from this test will help your doctor decide the best treatment for you.

Actual Coronary Angiography:

• At the time of angiography, you will be taken to the catheter room on a trolley.
• In the catheter room you will be put onto the X-ray table, which is quite narrow and firm
• The angiography is a sterile procedure and the staff will be wearing gowns and gloves.
• No visitors are permitted in this area.
• The insertion site will be washed with antiseptic and you will be partially covered with a sterile sheet.
• You will be connected to a machine to monitor your heart rate and blood pressure.
• A small needle will be placed suitably to allow medication to be given during the procedure.
• Local anaesthetic is injected into the areas where the catheter is to be inserted, which may sting a little. Usually this site is groin or wrist in case of radial angiography.
• The test is carried out by inserting a thin tube called catheter into an artery in the groin which is then passed upto the heart.
• When the catheter is in place, a small amount of colourless dye is injected and X-ray pictures are taken as it travels through coronary arteries.
• While the dye is being injected, you may feel a warm sensation in the chest and through the body.
• Please tell the doctor if you feel unwell during the procedure.
• The test takes approximately 15-20 minutes to complete.
• You will be awake during the angiogram and may be able to see the TV set showing your arteries.
• When the test is complete the catheter is removed from your groin.
• Firm pressure will be applied to the insertion site for 10 minutes until the bleeding has stopped.
• You may have a bandage put on the groin site.

After Your Coronary Angiography:

• You will be taken back to the ward on trolley or bed.
• You must keep your right leg straight and remain flat in bed for 6 hours. You may bend your other leg. This is to give the puncture site time to heal and help to prevent bleeding. A small lump may be present for a few days.
• Your blood pressure and pulse rate will be monitored periodically by the nursing staff. The puncture site and the foot pulse are checked regularly.
• Do not try to sit up until your nurse instructs you to do so. You can usually get out of the bed approximately six hours after returning to ward.
• The doctor will discuss the result of test with you. You will be given a letter for your family doctor with information about the results & treatment plan.
• A follow-up appointment will be organized for you before you leave the hospital.

Coronary Angioplasty:

What is Coronary Angioplasty: ( PTCA) ?

• Per Cutaneous : The procedure is done through the skin
• Transluminal : The procedure is done inside the artery.
• Coronary: An artery feeding the heart.
• Angioplasty : Opening up the narrowed portion of the artery.
• Blood flow to the heart muscle can be severely reduced due to narrowing inside the coronary arteries. This occurs because fatty deposits or plaques have built inside the coronary arteries.
• A lack of blood supply to the heart muscle may lead to angina or even a heart attack.
• PTCA is a procedure which improves the flow of blood to the heart by dialating the artery with a balloon tipped catheter,by the balloon compressing the plauque into the wall of the artery.This process provides a bigger opening and therefore better blood flow inside the artery.
• The actual procedure is very much like the coronary angiography you may have previously had.

The Day of Your Coronary Angioplasty:

• A small needle will be placed suitably at the back of your hand to allow intravenous fluids to be delivered before the procedure.
• The procedure is carried out by inserting a thin plastic tube (called catheter) to the heart from the artery in the groin or the wrist.
• The balloon tipped catheter is advanced to the site of the narrowing in the coronary artery.
• A small amount of colourless fluid (dye) is injected and X-ray images are taken to check the correct position. The balloon is then inflated for several seconds, one or more times as necessary.
• While the balloon is being inflated, you may feel some angina because the blood flow through the artery is temporarily blocked. This disappears as soon as the balloon has been deflated. Please tell the doctor if the pain continues. The cardiologist may put in a stent which is a small expandable tube to treat the narrowed artery or arteries. The doctor will discuss with you or your relatives regarding choice of the stent and the operation cost.
• The procedure takes approximately 60-90 minutes to complete.
• You will be shifted to Coronary Care Unit after the procedure for monitoring minimum upto 24 hours.

After your Coronary Angioplasty:

• A short plastic tube (sheath) in the groin will be left in place for approximately 2 to 4 hours after the procedure.
• When the sheath is removed from your groin the doctor or the qualified staff will press on the insertion site firmly for 20 minutes until the bleeding has stopped.
• A bandage will be applied on the groin site.
• You must keep your right leg straight and remain flat in the bed for 4 hours after the sheath has been removed.
• This is to give the puncture site to heal and help to prevent bleeding. A small tender lump may be present for a few days.
• Do not try to sit until your nurse instructs you to do so. You may bend your other leg. You can usually get out of the bed approximately 18-24 hours after returning to the ward.
• Your blood pressure, pulse rate, puncture site and foot pulses will be monitored closely by the nursing staff in coronary care unit.
• It is routine that your heart function will be monitored for 24 hours after the procedure. An electrocardiogram (ECG) will be taken when you get back to the ward and again before you go home.
• The doctor will discuss the results of the procedure.

Intravascular ultrasound (IVUS) is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology to see from inside blood vessels out through the surrounding blood column, visualizing the inner wall of blood vessels in living individuals.

The arteries of the heart (the coronary arteries) are the most frequent imaging target for IVUS. IVUS is used in the coronary arteries to determine the amount of atheromatous plaque built up at any particular point in the coronary artery. IVUS is of use to determine both plaque volume within the wall of the artery and/or the degree of stenosis of the artery lumen. It can be especially useful in situations in which angiographic imaging is considered unreliable; such as for the lumen of ostial lesions or where angiographic images do not visualize lumen segments adequately, such as regions with multiple overlapping arterial segments. It is also used to assess the effects of treatments of stenosis such as with hydraulic angioplasty expansion of the artery, with or without stents, and the results of medical therapy over time.

Intravascular ultrasound image of a coronary artery (left), with color-coding on the right, delineating the lumen (yellow), external elastic membrane (blue) and the atherosclerotic plaque burden (green). The percentage stenosis is defined as the area of the lumen (yellow) divided by the area of the external elastic membrane (blue) times 100. As the plaque burden increases, the lumen size will decrease and the degree of stenosis will increase.

Fractional flow reserve (FFR) is a technique used in coronary catheterization to measure pressure differences across a coronary artery stenosis (narrowing, usually due to atherosclerosis) to determine the likelihood that the stenosis impedes oxygen delivery to the heart muscle.

Fractional flow reserve is defined as the pressure behind (distal to) a stenosis relative to the pressure before the stenosis. The result is an absolute number; an FFR of 0.80 means that a given stenosis causes a 20% drop in blood pressure. In other words, FFR expresses the maximal flow down a vessel in the presence of a stenosis compared to the maximal flow in the hypothetical absence of the stenosis.

Procedure

During coronary catheterization, a catheter is inserted into the femoral (groin) or radial arteries (wrist) using a sheath and guide wire. FFR uses a small sensor on the tip of the wire (commonly a transducer) to measure pressure, temperature and flow to determine the exact severity of the lesion. This is done during maximal blood flow (hyperaemia), which can be induced by injecting products such as adenosine. A pullback of the pressure wire is performed, and pressures are recorded across the vessel.

ROTABLATION

The rotablator is a device inserted into your artery through a tube known as a catheter. Once in your blood vessel, the rotablator spins between 140,000 and 200,000 revolutions per minute. A diamond-tipped burr on the head of the device breaks plaque build up inside the artery. These smaller bits of plaque then harmlessly travel through the blood stream and are eventually eliminated from the body. This procedure is known as Rotablation or rotational atherectomy.

PROCEDURE

During the procedure, you might have a temporary pacemaker installed to prevent your heart rate from dropping too low. This will be removed after the procedure is completed. You will be awake during the procedure and given a local anaesthetic. The doctor will make a small incision at the top of your thigh and feed the catheter into a blood vessel. He will use an x-ray camera to determine where the catheter is. A dye will be injected so that your doctor can get a picture of the amount of blockage in your artery. A second catheter is inserted into a blood vessel. At the end of this tube is the rotablator. Once your doctor has the device in place, he turns the motor on to break the plaque off the walls of the artery. Some devices have a pouch to collect the plaque, others have a vacuum, but most simply allow the broken plaque to return to the blood stream. It will be in small enough pieces that the body will be able to process and eliminate it from the body.

Electrophysiology study An electrophysiology study (EP study) is a minimally invasive procedure that tests the electrical conduction system of the heart to assess the electrical activity and conduction pathways of the heart. During EPS, sinus rhythm as well as supraventricular and ventricular arrhythmias of baseline cardiac intervals is recorded.^[1] The study is indicated to investigate the cause, location of origin, and best treatment for various abnormal heart rhythms. This type of study is performed by an electrophysiologist and using a single or multiple catheters situated within the heart through a vein or artery. Procedure

This procedure is performed in a cath lab, which is a specially equipped operating room. More modern cath labs contain a video X-ray machine and large magnets (2-3 tesla, 2 ft. diameter) for manipulating the electrodes, in addition to other necessary equipment.

An IV tube is generally inserted to keep the patient hydrated and to allow for the administration of sedatives, anesthesia, or drugs.

In order to reach the heart with a catheter, a site will be prepared that will allow access to the heart via an artery or vein, usually in the wrist or groin. This site is then described as the insertion point.

A metal plate is placed underneath the patient between the shoulder blades, directly under the heart. An automated blood pressure cuff is placed on the arm, which periodically measures the patient’s blood pressure. A pulse oximeter is placed on one of the patient’s fingers, which steadily monitors the patient’s pulse and oxygen saturation of the blood.

The insertion point is cleanly shaved and sterilized. A local anesthetic is injected into the skin to numb the insertion point. A small puncture is then made with a needle in either the femoral vein in the groin or the radial vein in the wrist, before a guide wire is inserted into the venous puncture. A plastic sheath (with a stiffer plastic introducer inside) is then threaded over the wire and pushed into the vein (the Seldinger technique). The wire is then removed and the side-port of the sheath is aspirated to ensure venous blood flows back. It is then flushed with saline. Catheters are inserted using a long guide wire and moved toward the heart. Once in position, the guide wire is then removed.

EP Study

Once the catheter is in and all preparations are complete elsewhere in the lab, the EP study begins. The two large magnets are brought in on either side of the patient. They are large and looming and will sandwich the patient, but are able to precisely control the position of the electrodes that are on the end of the catheters. The X-ray machine will give the doctor a view of the heart and the position of the electrodes, and the magnets will allow the doctor to guide the electrodes through the heart. The magnets are controlled with either a joystick or game controller. The electrophysiologist begins by moving the electrodes along the conduction pathways and along the inner walls of the heart, measuring the electrical activity along the way.

The next step is pacing the heart, this means he/she will speed up or slow down the heart by placing the electrode at certain points along the conductive pathways of the heart and literally controlling the depolarization rate of the heart. The doctor will pace each chamber of the heart one by one, looking for any abnormalities. Then the electrophysiologist tries to provoke arrhythmias and reproduce any conditions that have resulted in the patient’s placement in the study. This is done by injecting electric current into the conductive pathways and into the endocardium at various places. Last, the electrophysiologist may administer various drugs (proarrhythmic agents) to induce arrhythmia. If the arrhythmia is reproduced by the drugs, the electrophysiologist will search out the source of the abnormal electrical activity. The entire procedure can take several hours.

Ablation

If at any step during the EP study the electrophysiologist finds the source of the abnormal electrical activity, he/she may try to ablate the cells that are misfiring. This is done using high-energy radio frequencies (similar to microwaves) to effectively "cook" the abnormal cells. This can be painful with pain felt in the heart itself, the neck and shoulder areas. A more recent method of ablation is cryoablation, which is considered less risky and less painful.